It has often been a complaint of most home owners that basements below ground level tend to have a musty odour. Furthermore it has been found that moisture accumulates in a basement, which contributes to this musty damp odour. Moisture can be removed from the air by cooling the air below its dew-point, which results in the condensation of the vapor and its subsequent removal as a liquid. One of the techniques that dehumidifier devices use to accomplish this is by use of a surface cooling technique in which air is passed over tubes cooled by a refrigerant flowing through them to cool the air below its dew-point and thereby cause the water vapor to condense out. As can be appreciated these processes require the expenditure of large amounts of energy in order to reach an acceptable level of relative humidity in a room. It is this cost factor that has been a deterrent to most home owners installing effective dehumidifiers in their basement.